I see scenarios like the following not impossible.
90% of the human population dies from a plague/​meteor along with the knowledge/​sufficient numbers to maintain things like power plants, steel mills and the trappings of modern life. Those people that are left with the knowledge have to spend all their time subsistence farming just to survive.
A few generations later when the population has increased a bit and subsistence farming improved in yield due to experience. People want to recreate technology, with just the knowledge passed down by word of mouth.
I see scenarios like the following not impossible.
90% of the human population dies from a plague/​meteor along with the knowledge/​sufficient numbers to maintain things like power plants, steel mills and the trappings of modern life. Those people that are left with the knowledge have to spend all their time subsistence farming just to survive.
A few generations later when the population has increased a bit and subsistence farming improved in yield due to experience. People want to recreate technology, with just the knowledge passed down by word of mouth.